Freeze drying is the drying of an already deep-frozen product in a vacuum, below the triple point of the solvent, i.e., water, present with the solid matter of the product. The vacuum allows the ice to turn directly into vapor without first passing through the liquid stage, in a sublimation process. This ensures that the product retains most of its original shape, color, taste, and nutrients.
Basically, there are four important steps in a freeze drying process: freezing the product; loading the frozen product into suitable trays (or vice versa); freeze drying the product in vacuum; and unloading the dry product afterwards. It is possible to add steps in the process for further optimization of the product or it characteristics.
There are two basic ways of drying the product in a production line. One way is in the form of batch operation, one example of an apparatus for carrying out batch freeze drying is the GEA Niro RAY™, and the other is in the form of continuous operation, one example being the GEA Niro CONRAD™.
Throughout the freeze drying process, there is a need for handling the product. In the above examples of prior art apparatus, the product is loaded into trays that are brought into and out of the individual operational units.
Within the bioindustry there is an increasing interest in providing products of a high quality under controlled conditions, and a number of guidelines and regulations have been formulated during recent years to establish proper quality measurement, analysis and control.
Presently, non-continuous systems are relatively slow processes, requiring substantial time for loading and unloading the product into and out of the individual operational units. The handling of trays and trolleys takes place with a partly manual operation. Furthermore, there is a risk of defrosting product during the transportation steps.
When handling products such as bacterial cultures, etc., particular requirements are necessary to meet the demands of such biograde systems.
Thus, a need exists to overcome the problems with the prior art systems, designs, and processes as discussed above.